Most states have a zero-tolerance (or near zero-tolerance) blood alcohol concentration (BAC) level of .02 for drivers under the legal drinking age (usually 21) that will result in a DUI/DWI charge. Some states set the BAC level at which a minor may be charged with DUI/DWI at .05. And some states will charge a minor driving a vehicle with a BAC of less than the state’s per se intoxication level (usually .08) with violating a zero-tolerance law such as driving while ability impaired (DWAI)—but will charge a minor with a BAC of .08 or more with per se (pronounced purr-say) DUI/DWI based on the state’s BAC-level definition of intoxication—or, in the absence of a chemical test of blood, breath, or urine, will charge the minor with common law DUI/DWI based on the police officer’s belief the minor was driving while intoxicated.

DUI/DWI criminal offenses, punishments, and terms used for underage DUI/DWI vary from state to state. These laws are generally located in a state’s statutes—often in the penal code or criminal code.

In Louisiana (LA), the state enforces a zero-tolerance policy for underage drinking and driving. The legal drinking age is 21, and for drivers under this age, the state has set a blood alcohol concentration (BAC) limit of 0.02 percent. If an underage driver is found operating a vehicle with a BAC of 0.02 percent or higher, they can be charged with a DUI (Driving Under the Influence). Should the BAC of a minor reach 0.08 percent or more, the charge escalates to the standard DUI offense, which is the same as for drivers of legal drinking age. This is based on the state's per se intoxication level. Additionally, even without a chemical test, a minor could face DUI charges if a police officer has reason to believe the minor was driving while intoxicated. The specific offenses, penalties, and terminology for underage DUI/DWI can be found within Louisiana's statutes, typically in the penal or criminal code.